[deliverable/linux.git] / net / ceph / pagevec.c

#include <linux/ceph/ceph_debug.h>

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/namei.h>
#include <linux/writeback.h>

#include <linux/ceph/libceph.h>

/*
 * build a vector of user pages
 */
struct page **ceph_get_direct_page_vector(const void __user *data,
					  int num_pages, bool write_page)
{
	struct page **pages;
	int got = 0;
	int rc = 0;

	pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
	if (!pages)
		return ERR_PTR(-ENOMEM);

	down_read(&current->mm->mmap_sem);
	while (got < num_pages) {
		rc = get_user_pages(current, current->mm,
		    (unsigned long)data + ((unsigned long)got * PAGE_SIZE),
		    num_pages - got, write_page, 0, pages + got, NULL);
		if (rc < 0)
			break;
		BUG_ON(rc == 0);
		got += rc;
	}
	up_read(&current->mm->mmap_sem);
	if (rc < 0)
		goto fail;
	return pages;

fail:
	ceph_put_page_vector(pages, got, false);
	return ERR_PTR(rc);
}
EXPORT_SYMBOL(ceph_get_direct_page_vector);

void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
{
	int i;

	for (i = 0; i < num_pages; i++) {
		if (dirty)
			set_page_dirty_lock(pages[i]);
		put_page(pages[i]);
	}
	if (is_vmalloc_addr(pages))
		vfree(pages);
	else
		kfree(pages);
}
EXPORT_SYMBOL(ceph_put_page_vector);

void ceph_release_page_vector(struct page **pages, int num_pages)
{
	int i;

	for (i = 0; i < num_pages; i++)
		__free_pages(pages[i], 0);
	kfree(pages);
}
EXPORT_SYMBOL(ceph_release_page_vector);

/*
 * allocate a vector new pages
 */
struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
{
	struct page **pages;
	int i;

	pages = kmalloc(sizeof(*pages) * num_pages, flags);
	if (!pages)
		return ERR_PTR(-ENOMEM);
	for (i = 0; i < num_pages; i++) {
		pages[i] = __page_cache_alloc(flags);
		if (pages[i] == NULL) {
			ceph_release_page_vector(pages, i);
			return ERR_PTR(-ENOMEM);
		}
	}
	return pages;
}
EXPORT_SYMBOL(ceph_alloc_page_vector);

/*
 * copy user data into a page vector
 */
int ceph_copy_user_to_page_vector(struct page **pages,
					 const void __user *data,
					 loff_t off, size_t len)
{
	int i = 0;
	int po = off & ~PAGE_CACHE_MASK;
	int left = len;
	int l, bad;

	while (left > 0) {
		l = min_t(int, PAGE_CACHE_SIZE-po, left);
		bad = copy_from_user(page_address(pages[i]) + po, data, l);
		if (bad == l)
			return -EFAULT;
		data += l - bad;
		left -= l - bad;
		po += l - bad;
		if (po == PAGE_CACHE_SIZE) {
			po = 0;
			i++;
		}
	}
	return len;
}
EXPORT_SYMBOL(ceph_copy_user_to_page_vector);

void ceph_copy_to_page_vector(struct page **pages,
				    const void *data,
				    loff_t off, size_t len)
{
	int i = 0;
	size_t po = off & ~PAGE_CACHE_MASK;
	size_t left = len;

	while (left > 0) {
		size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);

		memcpy(page_address(pages[i]) + po, data, l);
		data += l;
		left -= l;
		po += l;
		if (po == PAGE_CACHE_SIZE) {
			po = 0;
			i++;
		}
	}
}
EXPORT_SYMBOL(ceph_copy_to_page_vector);

void ceph_copy_from_page_vector(struct page **pages,
				    void *data,
				    loff_t off, size_t len)
{
	int i = 0;
	size_t po = off & ~PAGE_CACHE_MASK;
	size_t left = len;

	while (left > 0) {
		size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);

		memcpy(data, page_address(pages[i]) + po, l);
		data += l;
		left -= l;
		po += l;
		if (po == PAGE_CACHE_SIZE) {
			po = 0;
			i++;
		}
	}
}
EXPORT_SYMBOL(ceph_copy_from_page_vector);

/*
 * Zero an extent within a page vector.  Offset is relative to the
 * start of the first page.
 */
void ceph_zero_page_vector_range(int off, int len, struct page **pages)
{
	int i = off >> PAGE_CACHE_SHIFT;

	off &= ~PAGE_CACHE_MASK;

	dout("zero_page_vector_page %u~%u\n", off, len);

	/* leading partial page? */
	if (off) {
		int end = min((int)PAGE_CACHE_SIZE, off + len);
		dout("zeroing %d %p head from %d\n", i, pages[i],
		     (int)off);
		zero_user_segment(pages[i], off, end);
		len -= (end - off);
		i++;
	}
	while (len >= PAGE_CACHE_SIZE) {
		dout("zeroing %d %p len=%d\n", i, pages[i], len);
		zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
		len -= PAGE_CACHE_SIZE;
		i++;
	}
	/* trailing partial page? */
	if (len) {
		dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
		zero_user_segment(pages[i], 0, len);
	}
}
EXPORT_SYMBOL(ceph_zero_page_vector_range);
Commit	Line	Data
3d14c5d2 YS	1	#include <linux/ceph/ceph_debug.h>
	2
	3	#include <linux/module.h>
	4	#include <linux/sched.h>
	5	#include <linux/slab.h>
	6	#include <linux/file.h>
	7	#include <linux/namei.h>
	8	#include <linux/writeback.h>
	9
	10	#include <linux/ceph/libceph.h>
	11
	12	/*
	13	* build a vector of user pages
	14	*/
b324814e	15	struct page *ceph_get_direct_page_vector(const void __user data,
b6aa5901	16	int num_pages, bool write_page)
3d14c5d2 YS	17	{
3d14c5d2 YS	18	struct page **pages;
38815b78 SW	19	int got = 0;
38815b78 SW	20	int rc = 0;
3d14c5d2 YS	21
	22	pages = kmalloc(sizeof(pages) num_pages, GFP_NOFS);
	23	if (!pages)
	24	return ERR_PTR(-ENOMEM);
	25
	26	down_read(&current->mm->mmap_sem);
38815b78 SW	27	while (got < num_pages) {
	28	rc = get_user_pages(current, current->mm,
	29	(unsigned long)data + ((unsigned long)got * PAGE_SIZE),
	30	num_pages - got, write_page, 0, pages + got, NULL);
	31	if (rc < 0)
	32	break;
	33	BUG_ON(rc == 0);
	34	got += rc;
	35	}
3d14c5d2	36	up_read(&current->mm->mmap_sem);
38815b78	37	if (rc < 0)
3d14c5d2 YS	38	goto fail;
	39	return pages;
	40
	41	fail:
38815b78	42	ceph_put_page_vector(pages, got, false);
3d14c5d2 YS	43	return ERR_PTR(rc);
	44	}
	45	EXPORT_SYMBOL(ceph_get_direct_page_vector);
	46
b6aa5901	47	void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
3d14c5d2 YS	48	{
	49	int i;
	50
b6aa5901 HC	51	for (i = 0; i < num_pages; i++) {
	52	if (dirty)
	53	set_page_dirty_lock(pages[i]);
3d14c5d2	54	put_page(pages[i]);
b6aa5901	55	}
2b777c9d AV	56	if (is_vmalloc_addr(pages))
	57	vfree(pages);
	58	else
	59	kfree(pages);
3d14c5d2 YS	60	}
	61	EXPORT_SYMBOL(ceph_put_page_vector);
	62
	63	void ceph_release_page_vector(struct page **pages, int num_pages)
	64	{
	65	int i;
	66
	67	for (i = 0; i < num_pages; i++)
	68	__free_pages(pages[i], 0);
	69	kfree(pages);
	70	}
	71	EXPORT_SYMBOL(ceph_release_page_vector);
	72
	73	/*
	74	* allocate a vector new pages
	75	*/
	76	struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
	77	{
	78	struct page **pages;
	79	int i;
	80
	81	pages = kmalloc(sizeof(pages) num_pages, flags);
	82	if (!pages)
	83	return ERR_PTR(-ENOMEM);
	84	for (i = 0; i < num_pages; i++) {
	85	pages[i] = __page_cache_alloc(flags);
	86	if (pages[i] == NULL) {
	87	ceph_release_page_vector(pages, i);
	88	return ERR_PTR(-ENOMEM);
	89	}
	90	}
	91	return pages;
	92	}
	93	EXPORT_SYMBOL(ceph_alloc_page_vector);
	94
	95	/*
	96	* copy user data into a page vector
	97	*/
	98	int ceph_copy_user_to_page_vector(struct page **pages,
b324814e	99	const void __user *data,
3d14c5d2 YS	100	loff_t off, size_t len)
	101	{
	102	int i = 0;
	103	int po = off & ~PAGE_CACHE_MASK;
	104	int left = len;
	105	int l, bad;
	106
	107	while (left > 0) {
	108	l = min_t(int, PAGE_CACHE_SIZE-po, left);
	109	bad = copy_from_user(page_address(pages[i]) + po, data, l);
	110	if (bad == l)
	111	return -EFAULT;
	112	data += l - bad;
	113	left -= l - bad;
	114	po += l - bad;
	115	if (po == PAGE_CACHE_SIZE) {
	116	po = 0;
	117	i++;
	118	}
	119	}
	120	return len;
	121	}
	122	EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
	123
903bb32e	124	void ceph_copy_to_page_vector(struct page **pages,
b324814e	125	const void *data,
3d14c5d2 YS	126	loff_t off, size_t len)
	127	{
	128	int i = 0;
	129	size_t po = off & ~PAGE_CACHE_MASK;
	130	size_t left = len;
3d14c5d2 YS	131
3d14c5d2 YS	132	while (left > 0) {
903bb32e AE	133	size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
903bb32e AE	134
3d14c5d2 YS	135	memcpy(page_address(pages[i]) + po, data, l);
	136	data += l;
	137	left -= l;
	138	po += l;
	139	if (po == PAGE_CACHE_SIZE) {
	140	po = 0;
	141	i++;
	142	}
	143	}
3d14c5d2 YS	144	}
	145	EXPORT_SYMBOL(ceph_copy_to_page_vector);
	146
903bb32e	147	void ceph_copy_from_page_vector(struct page **pages,
b324814e	148	void *data,
3d14c5d2 YS	149	loff_t off, size_t len)
	150	{
	151	int i = 0;
	152	size_t po = off & ~PAGE_CACHE_MASK;
	153	size_t left = len;
3d14c5d2 YS	154
3d14c5d2 YS	155	while (left > 0) {
903bb32e AE	156	size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
903bb32e AE	157
3d14c5d2 YS	158	memcpy(data, page_address(pages[i]) + po, l);
	159	data += l;
	160	left -= l;
	161	po += l;
	162	if (po == PAGE_CACHE_SIZE) {
	163	po = 0;
	164	i++;
	165	}
	166	}
3d14c5d2 YS	167	}
	168	EXPORT_SYMBOL(ceph_copy_from_page_vector);
	169
3d14c5d2 YS	170	/*
	171	* Zero an extent within a page vector. Offset is relative to the
	172	* start of the first page.
	173	*/
	174	void ceph_zero_page_vector_range(int off, int len, struct page **pages)
	175	{
	176	int i = off >> PAGE_CACHE_SHIFT;
	177
	178	off &= ~PAGE_CACHE_MASK;
	179
	180	dout("zero_page_vector_page %u~%u\n", off, len);
	181
	182	/* leading partial page? */
	183	if (off) {
	184	int end = min((int)PAGE_CACHE_SIZE, off + len);
	185	dout("zeroing %d %p head from %d\n", i, pages[i],
	186	(int)off);
	187	zero_user_segment(pages[i], off, end);
	188	len -= (end - off);
	189	i++;
	190	}
	191	while (len >= PAGE_CACHE_SIZE) {
	192	dout("zeroing %d %p len=%d\n", i, pages[i], len);
	193	zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
	194	len -= PAGE_CACHE_SIZE;
	195	i++;
	196	}
	197	/* trailing partial page? */
	198	if (len) {
	199	dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
	200	zero_user_segment(pages[i], 0, len);
	201	}
	202	}
	203	EXPORT_SYMBOL(ceph_zero_page_vector_range);
	204